This seems to be a Sainsbury's brand (link), a family of well-known leftists.

John Benjamin Sainsbury married Mabel Van den Bergh, an heiress from a Dutch Jewish family whose fortune was made in margarine. They had two sons, Alan Sainsbury and Robert Sainsbury. Alan Sainsbury joined the family firm in the same year as his youngest uncle (John Benjamin Sainsbury's youngest brother, Paul Sainsbury), who was almost 20 years younger than John Benjamin Sainsbury. Both Alan Sainsbury and Paul Sainsbury joined Sainsbury's in 1921. John Benjamin Sainsbury's sons, Alan and Robert, built the reputation of the business for quality and innovation. Having inherited both Victorian and Jewish traditions of philanthropy, they also set the tone of the family's prevailing left-liberal social conscience.